The cooperative control method of customer's appliances for stable operation of power systems in large penetration of PV.

Author(s):  
Eitaro Omine ◽  
Masahiro Asari ◽  
Hiromu Kobayashi
Author(s):  
Xu Pei-Zhen ◽  
Lu Yong-Geng ◽  
Cao Xi-Min

Background: Over the past few years, the subsynchronous oscillation (SSO) caused by the grid-connected wind farm had a bad influence on the stable operation of the system and has now become a bottleneck factor restricting the efficient utilization of wind power. How to mitigate and suppress the phenomenon of SSO of wind farms has become the focus of power system research. Methods: This paper first analyzes the SSO of different types of wind turbines, including squirrelcage induction generator based wind turbine (SCIG-WT), permanent magnet synchronous generator- based wind turbine (PMSG-WT), and doubly-fed induction generator based wind turbine (DFIG-WT). Then, the mechanisms of different types of SSO are proposed with the aim to better understand SSO in large-scale wind integrated power systems, and the main analytical methods suitable for studying the SSO of wind farms are summarized. Results: On the basis of results, using additional damping control suppression methods to solve SSO caused by the flexible power transmission devices and the wind turbine converter is recommended. Conclusion: The current development direction of the SSO of large-scale wind farm grid-connected systems is summarized and the current challenges and recommendations for future research and development are discussed.


2021 ◽  
Vol 13 (6) ◽  
pp. 168781402110284
Author(s):  
Weikang Kong ◽  
Jixin Wang ◽  
Dewen Kong ◽  
Yuanying Cong ◽  
Shuangshi Feng

With the rapid development of the world economic construction and the shortage of energy, it has become a hot research issue to realize the electrification of the vehicle driving system and improve energy efficiency. Most of the electric construction machinery power systems are characterized by low speed and high load. The coordinated driving of multiple motors can increase the output torque and improve the transmission efficiency of the machine on the basis of a compact layout. A novel configuration of electric construction vehicles based on multi-motor and single-speed and its driving torque distribution control method is presented in this paper. The detailed mathematical model is established and the simulation analysis is carried out based on it. The results show that the proposed multi-motor driving system with the control strategy can improve the overall efficiency in the condition of ensuring the driving force when the parameter matching and motors choosing reasonably.


Clean Energy ◽  
2021 ◽  
Vol 5 (2) ◽  
pp. 196-207
Author(s):  
Shoichi Sato ◽  
Yasuhiro Noro

Abstract The introduction of large-scale renewable energy requires a control system that can operate multiple distributed inverters in a stable way. This study proposes an inverter control method that uses information corresponding to the inertia of the synchronous generator to coordinate the operation of battery energy storage systems. Simulation results for a system with multiple inverters applying the control method are presented. Various faults such as line-to-line short circuits and three-phase line-to-ground faults were simulated. Two fault points with different characteristics were compared. The voltage, frequency and active power quickly returned to their steady-state values after the fault was eliminated. From the obtained simulation results, it was verified that our control method can be operated stably against various faults.


Energies ◽  
2018 ◽  
Vol 11 (7) ◽  
pp. 1834 ◽  
Author(s):  
Xiangwu Yan ◽  
Jiajia Li ◽  
Ling Wang ◽  
Shuaishuai Zhao ◽  
Tie Li ◽  
...  

The lack of inertia and damping mechanism of photovoltaic (PV) grid-connected systems controlled by maximum power point tracking (MPPT) poses a challenge for the safety and stability of the grid. Virtual synchronous generator (VSG) technology has attracted wide attention, since it can make PV grid-connected inverter present the external characteristics of a synchronous generator (SG). Nevertheless, traditional PV-VSG is generally equipped with an energy storage device, which leads to many problems, such as increased costs, space occupation, and post-maintenance. Thus, this paper proposes a two-stage improved PV-VSG control method based on an adaptive-MPPT algorithm. When PV power is adequate, the adaptive-MPPT allows the PV to change the operating point within a stable operation area to actualize system supply-demand, matching in accordance to the load or dispatching power demand; when PV power is insufficient, PV achieves traditional MPPT control to reduce power shortage; simultaneously, improved VSG control prevents the DC bus voltage from falling continuously to ensure its stability. The proposed control approach enables the two-stage PV-VSG to supply power to loads or connect to the grid without adding additional energy storage devices, the effectiveness of which in off-grid and grid-connected modes is demonstrated by typical simulation conditions.


Author(s):  
Xiang Liu ◽  
Xiaogeng Liang

To solve the multi-interceptor coordination problem and to intercept the target with impact angle constraint, a novel distributed cooperative control algorithm with impact angle constraint based on integrated guidance and control is proposed. First, the mathematic model of integrated guidance and control is established by combining the interceptor-target relative motion model with the dynamic equation of the interceptor on pitch plane. The time varying gain extended state observer is developed to estimate and compensate the unknown disturbance. Based on the estimated value and fast nonsingular dynamic surface sliding control method, the IGC algorithm of leader is given; Then, based on distributed cooperative "leader-follower" model, the cooperative control strategy of multi-interceptor is designed, and gives out speeds in two directions on pitch plane, which are transformed to the command of total velocity and trajectory angle based on kinematic relations. Finally, to control the follower, the time varying gain extended state observer and the dynamic surface sliding control method are adopted. The simulation results demonstrate the effectiveness of the distributed cooperative control algorithm.


2021 ◽  
Vol 850 (1) ◽  
pp. 012017
Author(s):  
J Shri Saranyaa ◽  
A Peer Fathima ◽  
Asutosh Mishra ◽  
Rushali Ghosh ◽  
Shalmali Das

Abstract Modern day scenario has an increasing power demand due to the growing development which indeed increases the load on the generation which might cause turbulence in the system and may bounce out of stability. The governor itself can’t handle such frequent load changes and adjust the generation amount to keep the frequency between the margins. This paper proposes an approach towards such predicament to incorporate an optimization method in order to ensure stability of the system despite the drastic changes in demand. Load frequency control is a control method for maintaining the frequency of the system during the change in demand. Use of controllers has proven to be effective in controlling the frequency deviations in the power systems and the response of the controller is further improved using optimization technique for better stability. The PID controller tuned by Particle Swarm Optimization is employed in multi-area system which reduces the time response by a considerable amount and the deviation settles much quicker despite the rapid load changes. The proposed controller is executed further for renewable energy sources connected to the individual areas and demonstration proves that the optimized controller is efficient enough in handling the frequency deviations when wind and solar with sunlight penetration is incorporated.


1988 ◽  
Vol 21 (11) ◽  
pp. 387-393 ◽  
Author(s):  
H. Sasaki ◽  
H. Yorino ◽  
T. Suizu ◽  
S. Yurino ◽  
R. Yokoyama ◽  
...  

Sign in / Sign up

Export Citation Format

Share Document